2019-07-15 v1.8.1 "Orpington Duck"

  This release collects incremental improvements to many aspects of the library.

  - Upgrading:
    VP8E_SET_CPUUSED now accepts values up to 9 for vp9.
    VPX_CTRL_VP9E_SET_MAX_INTER_BITRATE_PCT had a spelling fix (was VP8E).
    The --sdk-path option has been removed. If you were using it to build for
      Android please read build/make/Android.mk for alternatives.
    All PPC optimizations have been disabled:
      https://bugs.chromium.org/p/webm/issues/detail?id=1522.

  - Enhancements:
    Various changes to improve encoder rate control, quality and speed
      for practically every use case.

  - Bug fixes:
    vp9-rtc: Fix color artifacts for speed >= 8.

2019-01-31 v1.8.0 "Northern Shoveler Duck"

  This release focused on encoding performance for realtime and VOD use cases.

  - Upgrading:
    This adds and improves several vp9 controls. Most are related to SVC:
      VP9E_SET_SVC_FRAME_DROP_LAYER:
        - Frame dropping in SVC.
      VP9E_SET_SVC_INTER_LAYER_PRED:
        - Inter-layer prediction in SVC.
      VP9E_SET_SVC_GF_TEMPORAL_REF:
        - Enable long term temporal reference in SVC.
      VP9E_SET_SVC_REF_FRAME_CONFIG/VP9E_GET_SVC_REF_FRAME_CONFIG:
        - Extend and improve this control for better flexibility in setting SVC
          pattern dynamically.
      VP9E_SET_POSTENCODE_DROP:
        - Allow for post-encode frame dropping (applies to non-SVC too).
      VP9E_SET_SVC_SPATIAL_LAYER_SYNC:
        - Enable spatial layer sync frames.
      VP9E_SET_SVC_LAYER_ID:
        - Extend api to specify temporal id for each spatial layers.
      VP9E_SET_ROI_MAP:
        - Extend Region of Interest functionality to VP9.

  - Enhancements:
    2 pass vp9 encoding has improved substantially. When using --auto-alt-ref=6,
    we see approximately 8% for VBR and 10% for CQ. When using --auto-alt-ref=1,
    the gains are approximately 4% for VBR and 5% for CQ.

    For real-time encoding, speed 7 has improved by ~5-10%. Encodes targeted at
    screen sharing have improved when the content changes significantly (slide
    sharing) or scrolls. There is a new speed 9 setting for mobile devices which
    is about 10-20% faster than speed 8.

  - Bug fixes:
    VP9 denoiser issue.
    VP9 partition issue for 1080p.
    VP9 rate control improvments.
    Postprocessing Multi Frame Quality Enhancement (MFQE) issue.
    VP8 multithread decoder issues.
    A variety of fuzzing issues.

2017-01-04 v1.7.0 "Mandarin Duck"

  This release focused on high bit depth performance (10/12 bit) and vp9
  encoding improvements.

  - Upgrading:
    This release is ABI incompatible due to new vp9 encoder features.

    Frame parallel decoding for vp9 has been removed.

  - Enhancements:
    vp9 encoding supports additional threads with --row-mt. This can be greater
    than the number of tiles.

    Two new vp9 encoder options have been added:
      --corpus-complexity
      --tune-content=film

    Additional tooling for respecting the vp9 "level" profiles has been added.

  - Bug fixes:
    A variety of fuzzing issues.
    vp8 threading fix for ARM.
    Codec control VP9_SET_SKIP_LOOP_FILTER fixed.
    Reject invalid multi resolution configurations.

2017-01-09 v1.6.1 "Long Tailed Duck"

  This release improves upon the VP9 encoder and speeds up the encoding and
  decoding processes.

  - Upgrading:
    This release is ABI compatible with 1.6.0.

  - Enhancements:
    Faster VP9 encoding and decoding.
    High bit depth builds now provide similar speed for 8 bit encode and decode
    for x86 targets. Other platforms and higher bit depth improvements are in
    progress.

  - Bug Fixes:
    A variety of fuzzing issues.

2016-07-20 v1.6.0 "Khaki Campbell Duck"

  This release improves upon the VP9 encoder and speeds up the encoding and
  decoding processes.

  - Upgrading:
    This release is ABI incompatible with 1.5.0 due to a new 'color_range' enum
    in vpx_image and some minor changes to the VP8_COMP structure.

    The default key frame interval for VP9 has changed from 128 to 9999.

  - Enhancement:
    A core focus has been performance for low end Intel processors. SSSE3
    instructions such as 'pshufb' have been avoided and instructions have been
    reordered to better accommodate the more constrained pipelines.

    As a result, devices based on Celeron processors have seen substantial
    decoding improvements. From Indian Runner Duck to Javan Whistling Duck,
    decoding speed improved between 10 and 30%. Between Javan Whistling Duck
    and Khaki Campbell Duck, it improved another 10 to 15%.

    While Celeron benefited most, Core-i5 also improved 5% and 10% between the
    respective releases.

    Realtime performance for WebRTC for both speed and quality has received a
    lot of attention.

  - Bug Fixes:
    A number of fuzzing issues, found variously by Mozilla, Chromium and others,
    have been fixed and we strongly recommend updating.

2015-11-09 v1.5.0 "Javan Whistling Duck"

  This release improves upon the VP9 encoder and speeds up the encoding and
  decoding processes.

  - Upgrading:
    This release is ABI incompatible with 1.4.0. It drops deprecated VP8
    controls and adds a variety of VP9 controls for testing.

    The vpxenc utility now prefers VP9 by default.

  - Enhancements:
    Faster VP9 encoding and decoding
    Smaller library size by combining functions used by VP8 and VP9

  - Bug Fixes:
    A variety of fuzzing issues

2015-04-03 v1.4.0 "Indian Runner Duck"

  This release includes significant improvements to the VP9 codec.

  - Upgrading:
    This release is ABI incompatible with 1.3.0. It drops the compatibility
    layer, requiring VPX_IMG_FMT_* instead of IMG_FMT_*, and adds several codec
    controls for VP9.

  - Enhancements:
    Faster VP9 encoding and decoding
    Multithreaded VP9 decoding (tile and frame-based)
    Multithreaded VP9 encoding - on by default
    YUV 4:2:2 and 4:4:4 support in VP9
    10 and 12bit support in VP9
    64bit ARM support by replacing ARM assembly with intrinsics

  - Bug Fixes:
    Fixes a VP9 bitstream issue in Profile 1. This only affected non-YUV 4:2:0
    files.

  - Known Issues:
    Frame Parallel decoding fails for segmented and non-420 files.

2013-11-15 v1.3.0 "Forest"

  This release introduces the VP9 codec in a backward-compatible way.
  All existing users of VP8 can continue to use the library without
  modification. However, some VP8 options do not map to VP9 in the same manner.

  The VP9 encoder in this release is not feature complete. Users interested in
  the encoder are advised to use the git master branch and discuss issues on
  libvpx mailing lists.

  - Upgrading:
    This release is ABI and API compatible with Duclair (v1.0.0). Users
    of older releases should refer to the Upgrading notes in this document
    for that release.

  - Enhancements:
      Get rid of bashisms in the main build scripts
      Added usage info on command line options
      Add lossless compression mode
      Dll build of libvpx
      Add additional Mac OS X targets: 10.7, 10.8 and 10.9 (darwin11-13)
      Add option to disable documentation
      configure: add --enable-external-build support
      make: support V=1 as short form of verbose=yes
      configure: support mingw-w64
      configure: support hardfloat armv7 CHOSTS
      configure: add support for android x86
      Add estimated completion time to vpxenc
      Don't exit on decode errors in vpxenc
      vpxenc: support scaling prior to encoding
      vpxdec: support scaling output
      vpxenc: improve progress indicators with --skip
      msvs: Don't link to winmm.lib
      Add a new script for producing vcxproj files
      Produce Visual Studio 10 and 11 project files
      Produce Windows Phone project files
      msvs-build: use msbuild for vs >= 2005
      configure: default configure log to config.log
      Add encoding option --static-thresh

  - Speed:
      Miscellaneous speed optimizations for VP8 and VP9.

  - Quality:
      In general, quality is consistent with the Eider release.

  - Bug Fixes:
      This release represents approximately a year of engineering effort,
      and contains multiple bug fixes. Please refer to git history for details.

2012-12-21 v1.2.0

  This release acts as a checkpoint for a large amount of internal refactoring
  and testing. It also contains a number of small bugfixes, so all users are
  encouraged to upgrade.

  - Upgrading:
    This release is ABI and API compatible with Duclair (v1.0.0). Users
    of older releases should refer to the Upgrading notes in this
    document for that release.

  - Enhancements:
      VP8 optimizations for MIPS dspr2
      vpxenc: add -quiet option

  - Speed:
      Encoder and decoder speed is consistent with the Eider release.

  - Quality:
      In general, quality is consistent with the Eider release.

      Minor tweaks to ARNR filtering
      Minor improvements to real time encoding with multiple temporal layers

  - Bug Fixes:
      Fixes multithreaded encoder race condition in loopfilter
      Fixes multi-resolution threaded encoding
      Fix potential encoder dead-lock after picture resize

2012-05-10 v1.1.0 "Eider"

  This introduces a number of enhancements, mostly focused on real-time
  encoding. In addition, it fixes a decoder bug (first introduced in
  Duclair) so all users of that release are encouraged to upgrade.

  - Upgrading:
    This release is ABI and API compatible with Duclair (v1.0.0). Users
    of older releases should refer to the Upgrading notes in this
    document for that release.

    This release introduces a new temporal denoiser, controlled by the
    VP8E_SET_NOISE_SENSITIVITY control. The temporal denoiser does not
    currently take a strength parameter, so the control is effectively
    a boolean - zero (off) or non-zero (on). For compatibility with
    existing applications, the values accepted are the same as those
    for the spatial denoiser (0-6). The temporal denoiser is enabled
    by default, and the older spatial denoiser may be restored by
    configuring with --disable-temporal-denoising. The temporal denoiser
    is more computationally intensive than the spatial one.

    This release removes support for a legacy, decode only API that was
    supported, but deprecated, at the initial release of libvpx
    (v0.9.0). This is not expected to have any impact. If you are
    impacted, you can apply a reversion to commit 2bf8fb5 locally.
    Please update to the latest libvpx API if you are affected.

  - Enhancements:
      Adds a motion compensated temporal denoiser to the encoder, which
      gives higher quality than the older spatial denoiser. (See above
      for notes on upgrading).

      In addition, support for new compilers and platforms were added,
      including:
        improved support for XCode
        Android x86 NDK build
        OS/2 support
        SunCC support

      Changing resolution with vpx_codec_enc_config_set() is now
      supported. Previously, reinitializing the codec was required to
      change the input resolution.

      The vpxenc application has initial support for producing multiple
      encodes from the same input in one call. Resizing is not yet
      supported, but varying other codec parameters is. Use -- to
      delineate output streams. Options persist from one stream to the
      next.

      Also, the vpxenc application will now use a keyframe interval of
      5 seconds by default. Use the --kf-max-dist option to override.

  - Speed:
      Decoder performance improved 2.5% versus Duclair. Encoder speed is
      consistent with Duclair for most material. Two pass encoding of
      slideshow-like material will see significant improvements.

      Large realtime encoding speed gains at a small quality expense are
      possible by configuring the on-the-fly bitpacking experiment with
      --enable-onthefly-bitpacking. Realtime encoder can be up to 13%
      faster (ARM) depending on the number of threads and bitrate
      settings. This technique sees constant gain over the 5-16 speed
      range. For VC style input the loss seen is up to 0.2dB. See commit
      52cf4dc for further details.

  - Quality:
      On the whole, quality is consistent with the Duclair release. Some
      tweaks:

        Reduced blockiness in easy sections by applying a penalty to
        intra modes.

        Improved quality of static sections (like slideshows) with
        two pass encoding.

        Improved keyframe sizing with multiple temporal layers

  - Bug Fixes:
      Corrected alt-ref contribution to frame rate for visible updates
      to the alt-ref buffer. This affected applications making manual
      usage of the frame reference flags, or temporal layers.

      Additional constraints were added to disable multi-frame quality
      enhancement (MFQE) in sections of the frame where there is motion.
      (#392)

      Fixed corruption issues when vpx_codec_enc_config_set() was called
      with spatial resampling enabled.

      Fixed a decoder error introduced in Duclair where the segmentation
      map was not being reinitialized on keyframes (#378)